Need to find the direction angle for each vector. #10 and #12 please!

10)  - 45 degrees

12)  0 degrees

Step-by-step explanation:

10)

Find the x and y components that define the vector that joins C with D:

x-component: -4 - (-8) = - 4 + 8 = 4

y-component:  4 - 8 = -4

use the tangent function to find the angle :

12)

Find the x and y components that define the vector that joins A with B:

x-component: 7 - 4 = 3

y-component:  - 1 - (-1) = -1 + 1 = 0

use the tangent function to find the angle :